The Research On Multidimensional,Multi-Source And Multi-Layer Mass Transfer Model Of Pollutant Release In Building Materials

Man-made panels and paints,while widely used as decoration materials,continuously release a large amount of formaldehyde and volatile organic compounds（VOCs）,causing significant harm to the human body.Studying the mass transfer mechanism of formaldehyde and VOCs diffusion from the interior of building materials to the indoor environment is of great significance for controlling the release concentration of pollutants in building materials and improving indoor air quality.This article mainly studies the mass transfer laws of formaldehyde and VOCs in man-made panels and paints.Multidimensional mass transfer model of formaldehyde emission from wood-based panels.Based on the experimental data of formaldehyde emission from man-made panels exposed to different surfaces in the environmental chamber,a multi-dimensional mass transfer model for formaldehyde emission was established by introducing the mass balance integral equation.Combined with parameter optimization algorithm,compound Simpson formula and finite difference method,the experimental data of formaldehyde emission are simulated numerically,and the convergence and stability of the numerical algorithm are verified.Compared with the one-dimensional mass transfer model,the superiority of the calculation results of the multidimensional mass transfer model is confirmed,and it is further clarified that the formaldehyde content released from the side of the artificial panel cannot be ignored,and the changing trend of physical diffusion rate and the chemical reaction generation rate of formaldehyde in the artificial panel is revealed.2)Study on mass transfer model of VOCs in multi-source paints.Based on the experimental data of VOCs release from single and multi-source paints（primer and topcoat,etc.）,a multi-source mass transfer model for VOCs release was established,and the analytical solution was obtained.The experimental data of VOCs release from multi-source paints are simulated by parameter optimization,mass conservation and finite difference method to verify the convergence and stability of the algorithm.By comparing the calculation results of single-source model and multi-source mass transfer model,it is confirmed that the release concentration of pollutants in multi-source paints is not the superposition of the release concentration of pollutants in single-source paints.The change rule of the initial release concentration in the multi-source model was analyzed by using Lt_i,j.3)Study on mass transfer model of VOCs in multi-storey paints.Based on the experimental data of VOCs release from single-layer and multi-layer paints,a multi-layer mass transfer model for VOCs release was established,and the analytical solution was obtained.The release law of VOCs in multi-layer,multi-source and multi-layer mass transfer model was further studied.The key parameters are obtained from the single-layer paints mass transfer model,and the initial release concentration is obtained from the balance and mass conservation equation of the material/material interface.Compared with the literature,the effectiveness of the multi-layer and multi-source multi-layer mass transfer model is verified.The multi-dimensional,multi-source and multi-layer mass transfer model established in this paper provides a theoretical basis for formulating indoor air pollution prevention and control strategies,and lays a foundation for new methods and ideas for subsequent research.